When I was very young the certainty of the physical sciences appealed to me. Mendeleev’s periodic table showed how elegantly the elements repeated a simple pattern as atoms added electrons one at a time. Newton’s laws of motion were as exact as the theorems in my first intellectual love, plane geometry. Little did I know.

Of course, my teachers didn’t know either. “In 1927,” when I was in third grade, “Heisenberg invented his uncertainty relations, which put the cap on the great scientific revolution we call quantum theory,” Leon Lederman wrote in his splendid account of particle physics from Democritus and earlier to 1993 (The God Particle [Boston: Houghton Mifflin, 1993], 175). Came the revolution, and one thing physicists are certain of now is, in a word, uncertainty.

The macro-universe Isaac Newton described in the seventeenth century, the universe we live in, still works as Newton said it did. But inside an atom’s nucleus, it’s a whole new ball game, and the ball in that game, the electron, has no mass and a radius measured in 1990 at “less than .00000000000000001 inches” (Lederman, 142). In that hard-to-imagine world, physicists find they cannot be certain, only approximate.

Some of this uncertainty seems to leak back into our normal world. Meteorologists know pretty well at what temperature moisture in the air can condense into droplets and fall as rain, but they can’t tell us how much rain will fall at what time in any given place. So they resort to averages, statistics, like “The chance of rain on Thursday is 40 percent.” Meteorologists keep trying to predict weather more precisely, but physicists know there is much they cannot be precise about. If they can detect the velocity of an electron or other particle they cannot know its location, and vice versa.
Government agencies have been exercised recently over the year 2000 census. They ask: should everyone be counted, or would equally good or better information come from sampling and statistics? No doubt a compromise will be worked out, but in particle physics there can be no exact count.

Suppose a census taker was assigned to a very odd community; its transients are becoming residents and residents becoming transient. Where they come from and where they go they don’t tell even if they know. Any one of them may stay a day or two or a week or even less than an hour, or perhaps never leave, and even when they are “in the community,” they may or not be in the house when the census taker calls. I don’t pretend to understand quantum theory, but it seems to me what goes on in inner space may be something like life in this imagined community.